Audio mixer



FIG. 1 is a perspective view of a audio mixer;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top side view thereof; and,

FIG. 7 is a bottom surface view thereof. 

The ornamental design for a audio mixer, as shown and described. 